[patch] mdio-sun4i: oops in error handling in probe

[Dan Carpenter]

We could end up dereferencing an error pointer when we call
regulator_disable().

Fixes: 4bdcb1dd9feb ('net: Add MDIO bus driver for the Allwinner EMAC')
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>

diff --git a/drivers/net/phy/mdio-sun4i.c b/drivers/net/phy/mdio-sun4i.c
index f70522c..1352965 100644
--- a/drivers/net/phy/mdio-sun4i.c
+++ b/drivers/net/phy/mdio-sun4i.c
@@ -122,6 +122,7 @@ static int sun4i_mdio_probe(struct platform_device *pdev)
                        return -EPROBE_DEFER;
 
                dev_info(&pdev->dev, "no regulator found\n");
+               data->regulator = NULL;
        } else {
                ret = regulator_enable(data->regulator);
                if (ret)
@@ -137,7 +138,8 @@ static int sun4i_mdio_probe(struct platform_device *pdev)
        return 0;
 
 err_out_disable_regulator:
-       regulator_disable(data->regulator);
+       if (data->regulator)
+               regulator_disable(data->regulator);
 err_out_free_mdiobus:
        mdiobus_free(bus);
        return ret;